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RV-6A Performance vs. RV-7A's. Am I dreaming!

taverroi

taverroi

Well Known Member
Ok, so check this out. I owned and RV7A for a little over a year and put well over 100hrs on it. Performed very light aerobatics often. Beautiful plane. Loved it. Sold it and immiediatly found and bought my RV6A that I'm flying now.

So here's the thing. Either I'm dreaming or.....I dont know what.... It climbs faster, fly's faster, performs better in what seems to be every phase of flight and I'm enjoying flying it more than I ever did my 7A, and I thought that nothing could compare to my 7A in terms of performance and enjoyment that I had experienced. So is it just me? Is this rediculious? I believe that I sense these difference enough for them to significantly change my view of one vs. the other.

So here's the questions:

Have any others experienced the same thoughts or feelings? Is what I'm saying true? It does'nt really seem to compute. Its just I always thought the 7A was the "Improved" Successor of the 6A and it just has'nt played out that way..in my experience anyway.

Any other?

Tango
 
Kinda but not exactly.
7A had and IO-360M1B 190hp w/9.5 to 1 pistons and a wirlwind prop.
6A has a IO-360B2B 180hp w/9.2 to 1 pistons with a hartzell.

Tim
 
taverroi said:
7A EW 1145...Gross 2000
6A Ew 1165...Gross 1800
Click to expand...

My 6A's empty weight, was just a hair more. It's also a more nimble performer than some 7's around here. At least everyone that's flown it, has liked the feel of the controls. Probably wouldn't stack up against a "3", though.. :)
 
Absolutely true. My 6A is definately more nimble than my 7A was the feel of the stick is...well....better.
 
taverroi said:
Ok, so check this out. I owned and RV7A for a little over a year and put well over 100hrs on it. Performed very light aerobatics often. Beautiful plane. Loved it. Sold it and immiediatly found and bought my RV6A that I'm flying now.

So here's the thing. Either I'm dreaming or.....I dont know what.... It climbs faster, fly's faster, performs better in what seems to be every phase of flight and I'm enjoying flying it more than I ever did my 7A, and I thought that nothing could compare to my 7A in terms of performance and enjoyment that I had experienced. So is it just me? Is this rediculious? I believe that I sense these difference enough for them to significantly change my view of one vs. the other.

So here's the questions:

Have any others experienced the same thoughts or feelings? Is what I'm saying true? It does'nt really seem to compute. Its just I always thought the 7A was the "Improved" Successor of the 6A and it just has'nt played out that way..in my experience anyway.

Any other?

Tango
Click to expand...

This is true for the ease of build and the parts count that Van's has to carry in stock.............. Oh yes, and the gross wt. and a little extra fuel. But the six is amazing!!
 
RV6 vs RV7

The opposite progression is what I did.
I have had the RV6 first then the current RV7. They were sporting different props and engines.

The -6 was noticeably more nimble. Fuel was less at 36. Gross is less @1800.
The interior was close to same on each. Panel was at a different distance. Nothing really giving a reason to not be perfectly happy with the airframe of the 6. Near same size interior. Same width. Small tail.

My -6 had an 0-320 and senanich F/P prop. My issue was the take off and climb being modest on performance. I wanted more.

My -7 has an IO-360 w/Hartzel C/S prop. The difference in specs was what I was looking for. There is considerably more take off and climb performance. It is also slightly more efficient than the -6 if operated at comparable alt, temp and speeds. This efficiency is due to fuel injection vs carb giving better ability to lean the -7 w/ injection. The -7 also consistently feels more stable approaching for landings slow flight as well as at cruise. The 7 is heavier with the C/S prop, heavier engine, taller landing gear, longer wings, larger tail and larger fuel tanks (42.) I may have forgot some things. Others will bring up things I may have forgot. The 7 is easy to taxi with the larger rudder.

After owning and flying both I like the extra power and the C/S prop more than any difference in the airframes. If I had done my -6 with the engine and C/S prop it would have been fine to keep it.
 
Race Records RV-6A & RV-7A

I took the 55 SARL race records for the two aircraft types and sorted by race/date/speed so the aircraft in the same race are compared. The RV Red aircraft are 320 powered and the RV Blue aircraft are 360 powered but some aof the 360s are angle valve 360s with a base 200 hp and the others are 180 hp:

Race Date Class Aircraft Type Speed Kts Speed MPH
Taylor 100 2007 5/20/07 RV Blue RV-7A 178.27 205.15
Taylor 100 2007 5/20/07 RV Blue RV-6A 168.72 194.16
Wichita 300 7/17/07 RV Blue RV-6A 169.91 195.53
AirVenture Cup 2007 7/23/07 RV Blue RV-7A 186.91 215.09
AirVenture Cup 2007 7/23/07 RV Blue RV-6A 179.99 207.13
AirVenture Cup 2007 7/23/07 RV Red RV-6A 178.90 205.87
AirVenture Cup 2007 7/23/07 RV Blue RV-7A 161.02 185.30
Memphis 100, 2007 10/28/07 RV Blue RV-6A 176.86 203.52
Memphis 100, 2007 10/28/07 RV Blue RV-6A 158.66 182.59
Rocket 100, 2007 11/18/07 RV Blue RV-6A 176.33 202.92
Texoma 100, 2008 4/20/08 RV Blue RV-6A 188.36 216.80
Texoma 100, 2008 4/20/08 RV Red RV-6A 161.75 186.17
BCAF 150, 2008 5/4/08 RV Blue RV-6A 181.45 208.81
Colorado 150, 2008 6/29/08 RV Blue RV-6A 178.63 205.56
AirVenture Cup 2008 7/27/08 RV Blue RV-6A 194.56 223.89
AirVenture Cup 2008 7/27/08 RV Blue RV-7A 189.41 217.97
AirVenture Cup 2008 7/27/08 RV Blue RV-7A 184.87 212.74
AirCap 200 8/24/08 RV Blue RV-6A 185.16 213.08
Memphis 100 2008 10/19/08 RV Blue RV-6A 180.26 207.44
Rocket 100 2008 11/23/08 RV Blue RV-6A 183.83 211.55
Taylor 100 2009 3/16/09 RV Blue RV-6A 182.35 209.85
West Texas 100 2009 4/12/09 RV Blue RV-6A 164.12 188.86
Texoma 100 2009 5/31/09 RV Blue RV-7A 181.12 208.43
Texoma 100 2009 5/31/09 RV Blue RV-7A 169.93 195.55
Texoma 100 2009 5/31/09 RV Blue RV-7A 164.78 189.63
Tennessee Valley Air Race 2009 6/14/09 RV Blue RV-6A 178.98 205.97
Colorado 150 2009 7/23/09 RV Blue RV-7A 168.39 193.78
AirVenture Cup 2009 7/27/09 RV Blue RV-7A 171.31 197.14
AirVenture Cup 2009 7/27/09 RV Blue RV-7A 162.28 186.75
TVA II 2009 10/18/09 RV Red RV-6A 162.66 187.19
Rocket 100 2009 11/22/09 RV Red RV-7A 172.11 198.06
Taylor 150 4/11/10 RV Red RV-7A 165.94 190.96
Taylor 150 4/11/10 RV Blue RV-7A 133.88 154.06
West Texas 100 6/6/10 RV Blue RV-6A 178.04 204.89
Great NW Air Race 6/13/10 RV Red RV-6A 152.37 175.35
AirVenture Cup 2010 7/26/10 RV Blue RV-7A 179.97 207.11
AirVenture Cup 2010 7/26/10 RV Blue RV-6A 179.83 206.94
AirVenture Cup 2010 7/26/10 RV Blue RV-7A 168.83 194.29
Great Canadian Air Rally 2010 8/22/10 RV Blue RV-6A 169.62 195.20
Grace Flight 2010 10/2/10 RV Blue RV-6A 181.23 208.54
Tennessee Valley Air Race 2010 10/30/10 RV Blue RV-6A 187.52 215.83
Rocket 100, 2010 11/20/10 RV Blue RV-6A 192.80 221.87
Rocket 100, 2010 11/20/10 RV Blue RV-7A 161.50 185.85
Taylor 150, 2011 4/2/11 RV Blue RV-6A 183.41 211.07
Taylor 150, 2011 4/2/11 RV Blue RV-7A 175.58 202.06
Texoma 100, 2011 4/16/11 RV Blue RV-7A 175.24 201.58
Lone Star Air Rally 5/14/11 RV Blue RV-7A 177.68 204.48
Lone Star Air Rally 5/14/11 RV Blue RV-7A 177.55 204.32
Lone Star Air Rally 5/14/11 RV Red RV-6A 154.86 178.21
Lone Star Air Rally 5/14/11 RV Red RV-6A 144.92 166.77
Memorial 130, Terrell, TX 5/28/11 RV Blue RV-7A 167.99 193.32
Big Muddy, Carbondale, IL 6/4/11 RV Blue RV-7A 149.43 171.97
Big Sky Air Race 7/9/11 RV Blue RV-6A 165.48 190.44
Cleveland Texas Air Race 10/15/11 RV Blue RV-7A 176.25 202.83
Rocket 100, 2011 11/19/11 RV Blue RV-6A 163.43 188.08

Bob Axsom
 
Biggest Reason

Don't forget the wing Span. The 6 is a couple of feet shorter. I'm not an aeronautical engineer, but I believe that all other things equal, that should influence both the roll rate and the speed.
Terry, CFI
RV9A N323TP
 
Yep

....what I've said all along...much better feel!

You're learning, Tim:)

Fly down to Sebring and join us today.

Best,
 
6 and 7 differences

Look at the belly of the 7. The 6 has a V bottom, It follows the dihedral of the wings to the center. The 7 has a flat bottom due to the center section
I built a 6 and am a boater. Drive a flat bottom boat and drive a deep V
I have a friend that built both and Has a 7 now he also noticed the difference between the two and thought the 6 was more nimble
 
sheepdog said:
Look at the belly of the 7. The 6 has a V bottom, It follows the dihedral of the wings to the center. The 7 has a flat bottom due to the center section
I built a 6 and am a boater. Drive a flat bottom boat and drive a deep V
I have a friend that built both and Has a 7 now he also noticed the difference between the two and thought the 6 was more nimble
Click to expand...

The V on the bottom of the six is maybe 1.5 inches, I doubt that makes much of a difference. I think the span is the largest contributor to the more nimble feel of the 6.
 
Trailing edge radii

It's all about the radius of the control surface trailing edge!
When trouble shooting a heavy wing, and after checking alignment issues and correcting those first, we then lightly squeeze the trailing edge of the aileron opposite the direction of roll tendency. We are advised during construction to avoid a "bulging" trailing edge, as this can lead to aileron "hunting" and indistinct control feel. The RV9 ailerons have riveted trailing edges and the control feel is "much" stiffer than an RV with normal bent trailing edges. I flew a friends RV7 one time and couldn't believe how heavy and stiff the control feel was, that is, until I looked at his trailing edges. They were squeezed extremely tight. It felt the same as my friends RV9. All of the RV8's I have built have been quickbuilds, and the ailerons say RV8/7 on them. I never touch the trailing edges until I fly them first. I know that when adjusting for a heavy wing that the more I squeeze the more I will lose that "LIGHTNESS" every one of us covets! Recently while test flying my friends new RV8, I decided to increase the trailing edge of the heavy wings aileron instead of squeezing the light wing. I used a block of wood and a hammer and gently tapped the length of the trailing edge. I then test flew it.
THE AIRPLANE WAS NEARLY UNCONTROLLABLE!
Half stick deflection resulted in very little roll!!!
I nursed the plane around the pattern, landed, and then immediately squeezed that aileron and things returned to normal.
Another example is that I built 2 identical RV8's side by side a few years ago.
I sold one to a friend and we hangar together. I had been fighting a heavy wing and had squeezed my aileron significantly to correct it.
I didn't much notice the difference this made in my control "feel" until I flew my buddies plane later on. I never really checked his plane much for wing heaviness during test flying because we had the electric aileron trim and it never needed much trim to fly hands off. I just didn't want to disconnect the springs because it was a hassle. So I left it alone. So, basically his ailerons were just as they came from the QB factory. It was amazing how much lighter in roll his airplane felt.
I would suspect that trailing edge radii versus control feel is applicable to elevator and rudder also.
For these reasons I believe that ALL "bent" trailing edge RV's should "feel" about the same if their trailing edges are identical.
 
jthocker said:
THE AIRPLANE WAS NEARLY UNCONTROLLABLE!
Half stick deflection resulted in very little roll!!!
Click to expand...

Really, Jon?? I can certainly see changing the shape a little bit having an effect on performance & roll rate, but "nearly uncontrollable" sounds a little extreme. That is unless by "gently tapping" the aft edge of the aileron you beat it until it lost all of it's aerodynamic properties (I'm thinking along the lines of an aft edge like a 2x4).

You sure you didn't somehow jam a control rod or something?
 
Everything that Mutha said.

The aileron bellcrank ratio is 1:1 on the -7, forget what it is on the -6 at the moment. One of my good friends cut up and rewelded the bellcrank assembly for a friend of ours to fix the poor aileron "feel" on a new RV-3B. It made a big difference in improving lightening the stick forces.
 
lostpilot28 said:
Really, Jon?? I can certainly see changing the shape a little bit having an effect on performance & roll rate, but "nearly uncontrollable" sounds a little extreme. That is unless by "gently tapping" the aft edge of the aileron you beat it until it lost all of it's aerodynamic properties (I'm thinking along the lines of an aft edge like a 2x4).

You sure you didn't somehow jam a control rod or something?
Click to expand...

Sorry Sonny, but I know what I'm talking about!!! It was EXTREME! No I didn't jam a control rod! In fact it was a 2 x 4, and it may have been gentle or it may have been "brisk", the point is, IS THAT THE TRAILING EDGE IS VERY SENSITIVE!!!
 
Stick pressures

I gotta say, the stick pressures are so beautifully balance on my new 6A. Noticeable different than my 7A. Its one of the first things I noticed when I began to fly it. I literally could tell a difference in that balance while on the ground still taxing. I even felt it in the rudder pedals..or I thought I did anyway.The builder of this plane has done and absolutely superb job.
 
6 vs 7

Have built a 6 and a 7. The six had an 0-320 150hp with a FP wood prop the 7 has an 0-360 with C/S. There was of course a remarkable difference in the take off and climb. Top end....not so much difference, maybe 6-8 kts. However even though the 6 had a slightly lighter feel to it, I like the increased fuel capacity and higher gross of the 7. It does rolls and loops quite nicely.


Ed Booth, RV-6, 7, 9A, & 10
 
It's also worth pointing out that stick length makes a huge difference as well. I've flown some where people cut off half of the stick so they could rest their hand on the grip cross country....but handled miserably when slow or trying to fly precise formation or horse it around the sky, not to mention a pain in the rear to land. If the 7 had any cut off the stick at all and the 6 didn't that makes a huge difference.

In the end, they are two slightly different airplanes. For the most part of the past 4 years we've had a 6 and a 7 in the barn, both with 360's and C/S props on them and weighed about the same. The 6 was definately more fun to toss around, but the 7 is better behaved in landing. The larger tail is a bit nicer (with less waggle) on the 7, but overall they are very close. Most would never be able to tell the difference (absent tailing edges on ailerons or stick lengths), but if flown back to back or you had lots of hours in them you can and will notice a difference. There are variables like John mentioned, as well as rigging, build quality, etc.. that will upset this standard so there isn't a hard/true statement regarding the handling qualities for every dash number of every RV.....just too many variables, but generalties are what I was referring to.

Just my 2 cents as usual.
Cheers,
Stein
 
SteinAir said:
It's also worth pointing out that stick length makes a huge difference as well. I've flown some where people cut off half of the stick so they could rest their hand on the grip cross country....but handled miserably when slow or trying to fly precise formation or horse it around the sky, not to mention a pain in the rear to land.
Click to expand...

I must be a bad pilot. My stick is probably cut down and I have my left hand on my leg while flying it. I don't do aerobatics but I think that I am flying the plane adequately and I am normally very good with my landings.
 
SteinAir said:
It's also worth pointing out that stick length makes a huge difference as well. I've flown some where people cut off half of the stick so they could rest their hand on the grip cross country....but handled miserably when slow or trying to fly precise formation or horse it around the
Click to expand...

Funny, now that you mention it. The pilot side stick is slightly longer than normal as the pilotside seat had....like 3 inches of leathered foam padding in it to raise the pilot up a bit. I had to remove it as I'm taller. This could be one of the factors I'm feeling I guess.
 
Aileron trailing edges

If you look at the ailerons on almost any high performance composite aerobatic plane, you will see a square trailing edge, often about 1/4" in height.
 
Ron Lee said:
I must be a bad pilot. My stick is probably cut down and I have my left hand on my leg while flying it. I don't do aerobatics but I think that I am flying the plane adequately and I am normally very good with my landings.
Click to expand...

Not saying that at all (wondering how you got all the way from point A to point L on that one because nothing of the sort was mentioned) just saying a plane with short sticks feels measurably worse than one without...that's it and thats a fact of physics. Guarantee if you horse one around with 6" sticks and then try one with longer sticks you'll see what I'm talking about. Really short sticks makes for a really stiff plane. Surprisingly, I've built them both ways so I've tried both. They are perfectly controllable either way, and slight cuts aren't a huge problem (and in fact needed in some instances), but the really short ones are noticably different to fly in most regimes except for cruise where it doesn't really matter.

That's the facts and my 2 cents!

Cheers,
Stein

PS, regarding trailing edges, like others have said....look at the trailing edges of airliners (and other speedy airplanes) then read up on the early test flight of spaceship one and what they had to do to the trailing edge.
 
SteinAir said:
Cheers,
Stein

PS, regarding trailing edges, like others have said....look at the trailing edges of airliners (and other speedy airplanes) then read up on the early test flight of spaceship one and what they had to do to the trailing edge.
Click to expand...

NO, just tell us...................... please.......:eek:
 
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